Conventionally, technology of image communications between devices which are connected via a public network has been utilized in a variety of styles.
For example, U.S. Pat. No. 5,084,769 (Date of Patent: Jan. 28, 1992) discloses a document management device which receives an image transmitted from a facsimile (fax) machine which is connected via the public network, extracts a document corresponding to the received image by searching a database, and transmits the document extracted out of the database to the fax machine. Utilizing the foregoing device, a user needs only to transmit an appropriate image (an image which requests the document management device to transmit a desired document) by an arbitrary fax machine so as to obtain a desired document under the management of the document management device. Thus, the user, regardless of where he or she is, can obtain a desired document, which is under the management of the document management device, by fax from anywhere he or she can use a fax machine which is connected to the public network.
Further, Japanese Unexamined Patent Publication No. 236047/1995 (Tokukaihei 7-236047 published on Sep. 5, 1995) discloses providing a main body of a fax machine used in image communications with a function (i) to read out a line number at a receiving end which is written on a document to be transmitted, (ii) to automatically request a station of the read-out line number to connect a line, and (iii) to transmit a document image once the line is connected. This fax machine does not require a user to input a line number at a receiving end by having the foregoing function, thereby improving controllability at the time of transmission.
On the other hand, the document management device of U.S. Pat. No. 5,084,769 has an arrangement in which, when receiving an image transmitted via the public network, i.e., a request for transmission of a document which is managed in a main body, the requested document is extracted out of a database without reservation so as to transmit it. Therefore, there has been a problem that anyone can freely obtain the document under the management of the document management device. That is, the conventional document management device could not manage, for example, a document which is disclosed only to a specific person, i.e., a document of a limited disclosure. Thus, there has been a problem that the conventional document management device fails to provide adequate security of documents managed in the main body.
Further, since, recently, there have been a plurality of service providers each of which provides communications lines and has its own tariff of charges for the use of a line, communications charges vary depending on a line used even when the same station is connected with lines (when the same station is used in communications). On the other hand, users wish to use a line of the least cost of communications if the same station is used to connect a line.
However, due to a fact that a service provider which provides the line of the least cost of communications is changed as a communications partner station is changed, it is difficult for a user to select a line for use depending on a communications partner with which a line is connected, and even if it was possible it will only be made at much expense in time and effort. With respect to this problem, there has been proposed a communications terminal device having a function to automatically select a line for use based on a line number which a user inputted [a so-called Least Cost Routing (LCR) function].
Meanwhile, recently, a network system which enables a user to obtain the same service by making access to any of server devices for providing information services (for example, the foregoing document management device) which are provided on a plurality of sites all over the country has been established. However, it should be noted that the LCR function is a function to select a line to connect stations at transmitting and receiving ends, but not to select a communications partner station requiring the least cost of communications out of a plurality of communications partner stations. Therefore, the user him/herself should have determined the server device (access point) with which the line is connected. This has raised such a problem that it is difficult to select a server device which always requires the least cost of communications, thereby wasting money on communications. Particularly, since there is a possible change of a server device requiring the least cost of communications in accordance with a change of a site where a terminal device for use is provided, it has been difficult for the user him/herself to select a server device requiring the least cost of communications when making access thereto while on a trip, for example.